Vehicle easy entry seat latching mechanism

ABSTRACT

An easy entry vehicle seat latch mechanism compatible with conventional inertia latch, recliner, and horizontal seat adjusting systems. A dual function easy entry latch mechanism is provided which initially unlatches a seat horizontal adjuster and subsequently resiliently holds the seat back in a forwardly tilted easy entry position. The mechanism allows the front seat to be readily traversed fore and aft either by a person standing outside the vehicle or by a rear seat passenger exiting the vehicle when the front seat is unoccupied.

The invention relates to an adjustable seat assembly for an automotivevehicle, and more particularly to a novel latching mechanism for a seatback inertia latch system providing easy entry of passengers to the rearseat area of the vehicle.

BACKGROUND OF THE INVENTION

The U.S. Pat. No. 4,440,442 to Drouillard et al discloses a seatposition control mechanism with an inboard slave track and outboardcontrol track arrangement having a pair of the same track assembliesarranged in vertically stacked relationship. One of the outboard trackassemblies provides for horizontal adjustment of the seat and the otherprovides for movement of the seat to and from an easy entry position. Acontrol cable arrangement interconnects a tilting seat back and latchmechanism for the other outboard track assembly to release a latchmechanism and permit movement of the seat to the easy entry position.

SUMMARY OF THE PRESENT INVENTION

The seat position control mechanism of this invention provides an easyentry vehicle seat arrangement having a dual acting seat back latchmechanism incorporating both horizontal seat cushion track adjustmentand resilient forwardly locked positioning of the seat back to an easyentry position. The seat assembly is adjusted for easy entry byinitially manually pivoting the upright seat back forwardly toward atilted and latched position. The initial forward tilting movement of aseat back self-actuating resilient latch mechanism unlatches the seattrack. Subsequent tilting of the seat back causes the latch mechanism tolock the seat back in a forward tilted position. The seat assembly isthus free for horizontal movement in a forward direction on the unlockedtrack for easy entry with the seat back held in its forwardly tiltedlocked position.

To return the seat assembly to a selected horizontal position theoperator slides the tilted seat back and seat cushion assemblyrearwardly on the unlocked track. When the rearward sliding effort onthe seat exceeds the seat back latch spring bias, the seat back unlocksallowing the operator to return the seat back to its upright position.The unlocking of the seat back causes the track latching assembly torelock the track. Thus, by selecting the point during the rearwardtravel of the seat cushion at which the seat back is returned to itsupright position the operator selects the horizontal location of theseat cushion. With the seat back in its upright position the operatormay also use the track control handle to horizontally adjust the seatcushion in a conventional manner.

It is thus a feature of the present invention to provide the improvedvehicle seat assembly described above having a dual self-actuating latchmechanism which permits easy rear seat entry by an operator pivoting theupright seat back to a forwardly tilted and latched position therebyinitially unlocking the seat cushion track and subsequently locking theseat back in a forward tilted mode enablying the seat to be moved to aneasy entry position.

A further object of the present invention is to provide an easy entryseat latch mechanism wherein the seat cushion can only be occupied by apassenger with the seat cushion horizontal adjustment track latched andthe seat back in its normal upright position.

It is still another object of the present invention to allow either anoperator standing outside the vehicle or a rear seat passenger toreadily control the horizontal adjustment of the seat cushion by varyingthe position at which the operator exerts a force on the forwardlylatched seat back when returning the seat assembly to a selectedhorizontal position.

These and other objects, features and advantages of the invention willbe apparent from the accompanying drawings and the detailed descriptionof the preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automotive seat assembly embodyingthe easy entry seat back latch arrangements of the invention;

FIG. 2 is a perspective view of the vehicle seat latching mechanism ofFIG. 1;

FIG. 3 is an enlarged elevational view of the seat back latch of FIG. 2shown unlatched and with the seat back in the normal upright position;

FIG. 3A is a fragmentary view of the seat back latch of FIG. 3 in itsintermediate position;

FIG. 4 is a view similar to FIG. 3 with the seat back latch shownlatched and with the seat back tilted forward;

FIG. 5 is a partial perspecitve view of the carrier latch portion of thetrack latching mechanism in its unlatched mode;

FIG. 6 is a fragmentary end elevational view taken of substantially onthe line 6--6 of FIG. 4;

FIG. 7 is a partially schematic side elevational view of the seatassembly of FIG. 1 shown in its normal aft position with the seat backpivoted forward from its dashed-line normal position to its latchedtilted position;

FIG. 8 is a view similar to FIG. 7 showing the seat assembly movedforward to its track unlocked easy enter position;

FIG. 9 is a view similar to FIG. 7 showing the seat cushion returned toits normal position from its dashed-line forward position with the seatback maintained in its latched tilted mode; and

FIG. 10 is a view similar to FIG. 7 showing the seat assembly in itsnormal track locked position and the seat back returned to its unlatchedupright mode with the track relatched.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1 a vehicle seat 10 according to the invention isshown positioned in the front or forward portion of the passengercompartment of a motor vehicle on the driver's side. Thus, the near sideof the seat assembly in FIG. 1 is the outboard side of the vehicle. Thevehicle seat 10 comprises a seat cushion 11 secured to the vehicle floor12, and a seat back 14.

The seat back 14 includes a frame structure, not shown, supporting thespring and fabric portions of the seat. The seat back frame structureprovides a sheet metal side hinge member 16. In FIG. 2 the hinge memberis shown with an upper arm 18 fixed to the seat back 14 and a lower arm20 fixed to a metal fitting portion 22 of the seat cushion frame. Asseen in FIGS. 3 and 4 the lower end of the upper hinge arm 18 is pinnedat 24 to the lower hinge arm 20.

A suitable coiled torsion spring reclining mechanism is generallyindicated in phantom outline at 26 in FIG. 2. An example of a typicalrecliner mechanism is shown in U.S. Pat. No. 4,337,978, and referencemay be had to that patent for an explanation thereof. The hinge member16 may also include an inertia latch system that permits free movementof the seat back 14 while preventing its forward movement when apredetermined relative acceleration occurs. As the inertia latchmechanism forms no part of the present invention it has been deletedfrom the drawings for the purpose of clarity. An example of one type ofinertia latch system suitable for use with the present invention isshown in U.S. Pat. No. 4,358,155 issued Nov. 9, 1982 to Osterhold et al.

A similar hinge member (not shown) is provided at the inboard side ofthe seat back 14. The hinge arms 18 and 20 coact to mount the seat back14 for pivotal movement relative to the seat cushion 11. The seat backpivots about a generally horizontal axis of the hinge pin 24 between theupright seating position of FIGS. 1, 2 and 3 and the forwardly tiltedand latched position of FIG. 4.

Seat 10 is supported on the vehicle for movement to a plurality ofhorizontally adjusted positions by a conventional track mechanism 28which includes an upper track member 30 and a lower track member 32. Theseat cushion 10 is connected to the upper C-sectioned track member 30and is slidable on the lower U-sectioned track member 32. Track member32 is mounted on the vehicle floor 12 by fore and aft brackets 34 and36, respectively. The upper track 30 has a latch member 37 pivotallymounted on the top thereof by means of a vertically extending pivot pin38 located in latch plate 39 and track member 30. A manually operablecontrol means in the form of a track lever 40, having a handle portion42, is fixedly attached to latch plate offset portion 44 (FIG. 5) byrivets 45. The latch offset portion 44 has a locking tab 46 extendinglaterally therefrom.

Upon manual rotation of the track lever 40 latch member 37 pivots aboutthe pivot pin 38 in a counter clockwise direction indicated by the arrow47 in FIG. 2. As a result the tab 46 is released from one of a series oflock openings 48 lanced in side flange 49 of the stationary lower trackmember 32. A coil tension spring 50 has one hooked end (not shown)connected to the aft end of the upper track member 30 and its otherhooked end 51 connected to latch offset portion 44. The spring 50 isoperative to urge or bias the lock tab 46 into engagement with one ofthe lock openings 48.

The latch plate 39 has one end of a pull rod 52 connected thereto by ahook portion 53. The rod 52 extends rearwardly with its aft end 54connected to the lower portion of a seat actuating lever 55. Theactuating lever 55 is pivotally connected to the Iower seat arm 20 bypivot pin 56 for pivotal movement about a transverse axis. As seen inFIG. 2 the upper end of the actuating lever 55 has a latch pin 58extending transversely inboard therefrom parallel to the axis of thepivot pin 56.

FIG. 2 shows the upper hinge arm 18 with a seat back latch mechanismgenerally indicated at 60. The latch mechanism 60 comprises a hook latchplate 62 and a striker plate 64 mounted in flush relationship. Thestriker plate 64 is fixedly secured to the upper hinge arm 18 by afastener 66 and a transverse pivot pin 68. The latch plate 62 issupported by pivot pin 68 for pivotal movement thereon relative to thestriker plate 64.

As best seen in FIGS. 3, 4 and 6 spring means, in the form of a wiretorsion spring 70, urges the latch plate 62 to its spring biasedclockwise rotational position. The biasing spring 70 has one end 72hooked on fastener 66 and its other end formed with an L-shaped bendproviding transverse finger portion 74 engaging an arcuate recess 76 inthe latch plate 62.

The striker plate forward end has an obtuse angled notch defined bycontact surfaces 78 and 80 providing a nose portion 82 with an inclinedcam surface 84. The latch plate 62 is located inboard of the actuatinglever 55 with the cam surface 84 is oriented rearwardly in spacedrelation to the latch pin 58. It will be observed in FIGS. 3 and 6, theinclined cam surface 84 engages the latch pin 58 when the seat back 14is initially moved forward. Upon the cam surface 84 engaging the latchpin 58 the actuating lever 55 is rotated counter-clockwise about pin 56causing the latch pin 58 to engage arcuate hook portion 86 of the latchplate 62.

As seen in FIG. 3A the latch plate 62 is rotated counter-clockwise aboutpin 68 against the force of biasing spring 70. The camming of the hookportion 86 below the contact surface 80 allows the pin 58 to slide intoengagement with the striker plate contact surface 78 as shown in FIG. 4.The seat back is thus latched in a forward titlted mode by virtue of thespring 70 returning the hook portion 86 to its biased position. It willbe noted that a stop pin 87 is located in latch plate 62 and engages thestriker plate 64, as seen in FIG. 3, to limit the biasing position ofthe latch plate.

The initial forward tilting of the seat back results incounter-clockwise pivotal rotation of the actuating lever 55. As aconsequence the pullrod 52 pivots the latch plate 39 and unlatches theupper track member 30 from the lower track member 32. Thus, the tiltingof the seat back allows the seat 10 to slide forward from its FIG. 7normal upright position to its FIG. 8 easy entry position with the seatback forwardly latched as shown in FIG. 4.

To return the seat 10 to its seat back upright mode the operator movesthe seat back 14 aft causing the seat cushion and its upper track member30 to slide rearwardly to a selected seating position shown in FIG. 9.When the track sliding effort on the moving seat exceeds the torsionspring 70 biasing force the latch plate 62 rotates counter clockwiseabout pivot pin 68 unlocking and releasing latch pin 58. The unlockingof the seat back releases tension on the track latch coil spring 50biasing the track latch member 37 clockwise to relatch the upper andlower track members. With the seat back 14 returned to its uprightseating mode of FIG. 10 the operator assumes a seated position. Theoperator may then use the track lever handle 42 to adjust the seat 10horizontally fore and aft in a conventional seat adjusting manner.

What is claimed is:
 1. An easy entry seat latch mechanism adapted for avehicle seat assembly including a seat cushion and a seat back, hingemeans providing pivotal movement of said seat back relative to said seatcushion about a generally horizontal first axis between a generallyupright normal position and a forwardly tilted position, track meansmounting said seat cushion on said vehicle for horizontal movement to aplurality of fore and aft horizontal adjusted positions, a tracklatching assembly on said track means and resiliently biased in a latchdirection by first spring means, said easy entry seat latching mechanismcomprising,a lever member rotatably supported on said hinge means forpivotal movement about a second axis substantially parallel to saidfirst axis; means connecting said lever member to said track latchingassembly such that said first spring means biases said lever member forrotation in a first track locking direction; a dual acting seat backlatch mechanism mounted on said seat back, said latch mechanismincluding second spring means biasing said latch mechanism into itslatched mode; said seat back latch mechanism initially operative, whensaid seat back is first pivoted forwardly to contact said lever membercausing said lever member to be rotated in a second direction wherebysaid track latching assembly is unlocked freeing said seat cushion forhorizontal movement on said track means to an easy entry forwardposition, said seat back latch mechanism subsequently operative uponsaid seat back being further pivoted to a forward tilted position tolockingly engage said lever member; and said seat cushion operative tobe moved rearwardly from its easy entry position to a selectedhorizontal position, whereby upon subsequent pivoting of said seat backto its upright position by a force sufficient to overcome the resilientbias of said second spring means causes said seat back latch mechanismto unlock said lever member for rotation of said lever member in saidfirst direction such that said first spring means returns said tracklatching assembly to a locked condition thereby maintaining said seatcushion in said selected horizontal position.
 2. The easy entry latchmechanism as set forth in claim 1 wherein said mechanism including astriker member and latch member, said striker member fixed on said seatback and said latch member rotatably supported on said striker memberfor pivotal movement about a third axis substantially parallel to saidfirst axis.
 3. The easy entry latching mechanism as set forth in claim 2wherein said lever member having its lower end connected to said tracklatching assembly and having a locking pin adjacent its upper end, andwherein said locking pin adapted to be engaged by said striker membercausing said lever member to rotate in said one direction whereby saidtrack latching assembly is unlatched.
 4. An easy entry seat latchmechanism adapted for a vehicle seat assembly including a seat cushionand a seat back, said seat back having an upper hinge arm securedthereto extending downwardly from one side thereof, said seat cushionhaving a lower hinge arm secured thereto extending upwardly from saidone side thereof, means connecting said upper and lower hinge armsproviding pivotal movement of said seat back relative to said seatcushion about a generally horitzontal first axis between a generallyupright normal position and a forwardly tilted position, track meansmounting said seat cushion on said vehicle for horizontal movement to aplurality of fore and aft horizontal adjusted positions, a tracklatching assembly rotatably supported on said track means andresiliently biased in a latching direction by first spring means, saideasy entry seat latch mechanism comprising;a lever member rotatablysupported on said lower hinge arm for pivotal movement about a secondaxis substantially parallel to said first axis; means connecting thelower end of said lever member to said track latching assembly such thatsaid first spring means biases said lever member for rotation in a firsttrack locking direction, said lever member having a locking pin adjacentits upper end; a seat back latch assembly including a striker member anda latch member, said striker member fixed on said upper hinge arm, saidlatch member rotatably supported on said striker member for pivotalmovement about a third axis substantially parallel to said first axis,and second spring means biasing said latch member for rotation in saidfirst direction; said seat back latch mechanism initially operative,when said seat back is first pivoted forwardly to contact said lockingpin causing said lever member to rotate in a second direction, wherebysaid track latching assembly is unlocked freeing said seat cushion forhorizontal movement on said track means to an easy entry forwardposition; said seat back latch mechanism subsequently operative uponsaid seat back being further pivoted to a forward tilted position tolockingly engage said locking pin; and said seat cushion operative to bemoved rearwardly from its easy entry position to a selected horizontalposition, whereby upon subsequent pivoting of said seat back to itsupright position by a force sufficient to overcome the resilient bias ofsaid second spring means causes said seat back latch mechanism to unlocksaid locking pin for rotation of said lever member in said firstdirection such that said first spring means returns said track latchassembly to a locked condition thereby maintaining said seat cushion insaid selected horizontal position.
 5. The easy entry seat latchingmechanism as set forth in claim 4 wherein said latch plate having a stoppin thereon adapted to engage said striker plate to define the lockedposition of said striker plate.